Malicious PDF — malware analysis report

Static analysis result for SHA-256 f8f51c73dcfba791…

MALICIOUS

PDF

40.9 KB Created: 2020-08-15 21:52:43 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: 09408e336c0c43b5b493beaf1fe550b3 SHA-1: 07b7c8848f1464f8b4234e7ce30adbc12ecb7b95 SHA-256: f8f51c73dcfba791c9116ef1dc47a7b008736cf595b4f2cf1f38d47fbe5c5327
152 Risk Score

Malware Insights

MITRE ATT&CK
T1566.002 Spearphishing Attachment T1059.001 PowerShell

The PDF contains a link to a known malicious redirector, ttraff.ru, which is designed to lead users to malicious content. The document body, though heavily obfuscated, contains the same URL and other URLs pointing to PDF files hosted on various domains, suggesting a link farm or SEO poisoning tactic. The ML classifier also strongly indicated maliciousness. The primary attack pattern involves luring the user to click the malicious link.

Machine Learning

  • Nyx PDF Classifier malicious score 1.0000

Heuristics 4

  • PDF links to known malicious redirector infrastructure critical PDF_MALICIOUS_REDIRECTOR_LINK
    PDF contains a clickable URI to redirector infrastructure used by a known malicious PDF SEO/adware delivery campaign. These documents typically rely on user interaction and redirect chains rather than a PDF parser vulnerability.
  • Small PDF contains mass external PDF link farm critical PDF_SEO_LINK_FARM
    Small PDF contains many clickable external PDF links, mostly clustered on one host. This matches generated SEO/link-farm PDF carriers used to route users into malicious or unwanted-software delivery chains, rather than a normal document citation pattern.
  • Object number defined twice with different bodies info PDF_DUPLICATE_OBJ_BODY_INCREMENTAL
    The same indirect object (N G) is defined more than once with different body bytes. First-wins and last-wins readers will resolve different content, which is a parser-confusion shape used by targeted PDFs. Body-only differences are common in benign incremental updates, so severity is raised only when the duplicate carries active content.
  • Embedded URL info EMBEDDED_URL
    One or more URLs were extracted from the document. The URL itself is not a detection — see the per-URL labels for which channel (macro, JS, link annotation, document body, ...) reached each URL.
    URL https://ttraff.ru/wb?keyword=o
    • http://files.hcsatl.com/uploads/1/3/1/4/131437616/4317416.pdf
    • http://zamezafi.dreamerpengh.com/uploads/1/3/0/7/130776485/2699329.pdf
    • http://files.jcnentertainment.com/uploads/1/3/1/3/131379409/loxemudewirat.pdf
    • http://files.legacy-318.com/uploads/1/3/1/4/131438432/zetenufataga.pdf
    • https://cdn.shopify.com/s/files/1/0434/3883/3831/files/70919270847.pdf
    • https://cdn.shopify.com/s/files/1/0432/9901/2766/files/46008944492.pdf
    • https://cdn.shopify.com/s/files/1/0433/8555/3061/files/gudopiwekosiwaxemute.pdf
    • https://cdn.shopify.com/s/files/1/0438/0426/2561/files/69314707540.pdf
    • https://cdn.shopify.com/s/files/1/0428/3210/1543/files/najazobebarikanu.pdf
    • https://cdn.shopify.com/s/files/1/0434/0088/8483/files/filsafat_humanisme_dan_renaissance.pdf
    • https://cdn.shopify.com/s/files/1/0431/9959/4656/files/18043353959.pdf
    • https://cdn.shopify.com/s/files/1/0451/6829/6090/files/rationalisation_questions_for_class_9.pdf
    • https://cdn.shopify.com/s/files/1/0430/3906/4225/files/13577784952.pdf
    • https://cdn.shopify.com/s/files/1/0431/2458/8701/files/30726442188.pdf
    • https://cdn.shopify.com/s/files/1/0430/2841/4618/files/autoit_complete_tutorial.pdf
    • https://cdn.shopify.com/s/files/1/0428/3033/2060/files/batch_convert_word_to_mac.pdf
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#
    • http://purl.org/dc/elements/1.1/
    • http://ns.adobe.com/pdf/1.3/
    • http://ns.adobe.com/xap/1.0/
    • http://ns.adobe.com/xap/1.0/mm/
    • http://ns.adobe.com/xap/1.0/rights/

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off00006172.bin
1aecf4c7d19dc7b2cbcb68165442a7b432fed5d6d3978d02607c90047848011a
pdf-font-stream PDF embedded font (sfnt) at offset 0x6172 5596 bytes
font_01_sfnt_off0000748a.bin
8750a9b33b5cd0d1d48118d2acd3f55a711d20f0f6206e900f3879a37db9fbb5
pdf-font-stream PDF embedded font (sfnt) at offset 0x748A 9880 bytes